The use of porcelain or synthetic artificial teeth in combination with denture plates and dental bridges is well known in the art. The artificial teeth permit the wearer to enjoy the benefits of teeth after the wearer's natural teeth have been removed. When the artificial teeth are used in combination with a denture plate then the teeth are secured to the plate and the plate is disposed over the gums of the wearer. There is a naturally occurring tendency for the gums of the wearer to shrink as the wearer ages with the result that mastication or chewing becomes increasingly difficult as the wearer is unable to apply sufficient pressure to the teeth to perform the mastication process. Additionally, the shrinkage of the gums causes the wearer to experience pain or discomfort because of the improper fitting of the plate with the gums.
An artificial tooth includes a tooth body and an upper crown surface. The crown includes a plurality of cusps extending from the crown and interdigitating with the cusps of an oppositely disposed aligned tooth. The interdigitation, of an upper tooth with a lower tooth, permits the mastication process to occur because of the grinding action occasioned by the movement of the cusps relative to each other when a food product is disposed between the teeth. The prior art artificial teeth required a complicated alignment process, with an equally complicated alignment apparatus, in order that the cusps of one tooth be properly interdigitated with the cusps of the oppositely aligned tooth. Should the cusps not be properly aligned, then the teeth will not function properly. Consequently, the prior art artificial teeth greatly increase the expense to the wearer due to the need for aligning the cusps.
Prange, U.S. Pat. No. 2,295,864, discloses an artificial tooth in which metal cusps are provided at generally the periphery of the crown in order to eliminate the need for aligning the cusps of the prior art artificial teeth, both synthetic and porcelain. The metal cusps of Prange while not requiring alignment of the cusps do increase the cost of artificial teeth as one metal cusp is provided for each artificial tooth. Additionally, the artificial teeth of Prange are individually molded and manufactured and each of the teeth must be individually secured to the plate. Furthermore, the metal cusps of Prange are difficult to manufacture and the securement of the metal cusps in the synthetic artificial teeth is a complicated procedure with the result of increased costs.
Howmedica, Inc., of 5101 South Keeler Avenue, Chicago, Ill., 60632, manufactures artificial teeth under the trade name Micromold Plastic Teeth and claims the benefit of the Prange patent. The artificial teeth of Howmedica are not, however, naturally appearing as the teeth depart quite dramatically from the visual effect of natural teeth. The Howmedica teeth includes three teeth which are interconnected and in which a zigzag cutter bar is disposed where the cusps of Prange were positioned. The Howmedica teeth do not have the natural look of real teeth because the zigzag of the cutter bar is disposed between the inner and outer side surfaces of the teeth with the effect that the teeth must conform to the shape of the cutter bar rather than the cutter bar conforming to the shape of the teeth. Additionally, the Howmedica cutter bar is secured in the teeth by the hardening of the synthetic resin and no means are provided for securely seating the cutter bar otherwise. Furthermore, the teeth of Howmedica are not naturally appearing as they lack the undercut associated with real teeth and this lack of undercut is due to the method of manufacture.
The present invention discloses and claims a unique cutter bar configuration which is adapted to permit the artificial synthetic teeth to be naturally appearing, including the undercuts associated with real teeth, while still permitting the mastication process without the need for interdigitating the cusps. The cutter bar of the present invention provides a series of crests which are disposed along the crown of a plurality of interconnected artificial synthetic teeth in a unique configuration which facilitates the mastication process when upper and lowcr teeth are employed. The manufacture of the teeth of the present invention is much simpler and less complicated than prior art artificial teeth manufacturing processes with the result that the cost of the teeth may be kept to a minimum. The cutter bar of the present invention also includes means for securely positioning the cutter bar means in the artificial teeth with the result that greater amounts of pressure may be applied to the cutter bar. Consequently, the disclosed invention provides a novel cutting bar means in combination with a plurality of interconnected longitudinally aligned artificial teeth which greatly facilitates the use of artificial teeth while reducing the cost to the ultimate consumer.